a = int(input("输入一个数："))
if a > 0:
    print("a>0")
elif a < 0:
    print("a<0")
else:
    print("a=0")


print("---------------------------")


a = int(input("输入一个数："))
if a % 2 == 0:
    print("偶数")
else:
    print("奇数")


print("---------------------------")


a1 =int(input("输入第一个整数："))
b1 =int(input("输入第二个整数："))
c1 =int(input("输入第三个整数："))
if a1 > b1:
    if b1 > c1:
        print("c1<b1<a1")
    elif c1 > b1:
        if c1 < a1:
            print("b1<c1<a1")
        elif c1 > a1:
            print("b1<a1<c1")
        else:
            print("忽略不计")
    else:
        print("忽略不计")
elif b1 > a1:
    if a1 > c1:
        print("c1<a1<b1")
    elif c1 > a1:
        if c1 > b1:
            print("a1<b1<c1")
        elif c1 < b1:
            print("a1<c1<b1")
        else:
            print("忽略不计")
    else:
        print("忽略不计")
else:
    print("忽略不计")

print("---------------------------------")

s1 = int(input("输入一个三位数："))
a = s1//100
b = s1//10%10
c = s1%10
if a**3 + b**3 + c**3 == s1:
    print("该数为水仙花数")

print('---------------------------------')

a = 2025
if a % 4 == 0 and a % 100 != 0:
    print("闰年")
elif a % 100 == 0 and a % 400 == 0:
    print("闰年")
else:
    print("平年")

print('----------------------------------')
'''
b = 1548
s1 = b//1000
s2 = b//100%10
s3 = b//10%10
s4 = b%10
if s1%2 == 0 and s2%2 == 0 and s3%2 == 0 and s4%2 == 0 :
    print('都为偶数')
if (s1%2  or s2%2  or s3%2  or s4%2) != 0:
    print('都为偶数')
if s1%2 == 0 and s2%2 == 0 and s3%2 == 0 and s4%2 == 0 :
    print('都为偶数')
if s1%2 == 0 and s2%2 == 0 and s3%2 == 0 and s4%2 == 0 :
    print('都为偶数')
    '''
print('------------------------------------')

a = 170
if ((a - 108)*2)-10 <= a <= ((a - 108)*2)+10:
    print("合适")
else:
    print("不合适")

print("------------------------------------")

s1 = int(input("输入的小时为："))
s2 = int(input("输入的分钟为："))
s3 = int(input("输入的秒数为："))
if s1 < 0 and s1 > 24:
    print("输入错误不在0-24的范围内")
elif s2 < 0 and s2 > 60:
    print("输入错误不在0-60的范围内")
elif s3 < 0 and s3 > 60:
    print("输入错误不在0-60的范围内")
else:
    print(f"{str(s1).zfill(2)}:{str(s2).zfill(2)}:{str(s3).zfill(2)}")


print("------------------------------------")
import math
a=10
b=12
c=10
if a + b > c and a + c > b and b + c >a:
    print("可以构成三角形")
    if a == b == c:
        print("等边三角形")
    elif a == b != c or  a == c != b or c == b != a:
        print("等腰三角形")
    elif a**2 == b**2 + c**2 or  b**2 == a**2 + c**2 or c**2 == b**2 + a**2:
    # elif abs(a ** 2 - (b ** 2 + c ** 2)) < 1e-9 or abs(b ** 2 - (a ** 2 + c ** 2)) < 1e-9 or abs(c ** 2 - (b ** 2 + a ** 2)) < 1e-9:
    # 直角三角形判断不准确：在实际编程中，由于浮点数精度问题，直接使用 a**2 == b**2 + c**2 进行判断可能会出现误差。可以考虑使用一个很小的误差范围（如 1e-9）来判断是否近似相等。
        print("直角三角形")
    else:
        print("普通三角形")
    s = (a + b + c)/2
    area = math.sqrt(s * (s - a) * (s - b) * (s - c))
    print(f"三角形面积为{area}")
else:
    print("不构成三角形")


print('-----------------------------------')


s1= input("输入一个字母（大小写均可）：")
if len(s1)==1 and s1.isalpha():
    if s1 == s1.upper():
        print(s1.lower())
    else:
        print(s1.upper())
else:
    print("输入错误")

print('-----------------------------------')







